The present invention relates to a mechanism for conveying a stream of books along a raceway and for removing defective books from the raceway.
Certain types of books, particularly paperback books, are assembled in a collator by feeding signatures from a series of hoppers each of which contains a supply of the same page or signature. A conveyor moves past the hoppers each of which delivers a signature in sequence until the book is assembled. The conveyor moves the assemblages along a raceway which supports the growing stack of signatures. The raceway is inclined in a direction transverse to the path of movement of the conveyor. A guide extends vertically upward along the lower edge of the raceway to prevent the assemblages from sliding down the inclined surface. Once the signatures have been assembled, they are carried on the conveyor to a binder where the back is glued in place and the pages or signatures are trimmed.
Occasionally one of the hoppers may misfeed, either feeding an extra signature or failing to feed any. In this case it is necessary to remove the not-yet bound book from the raceway so that it may be repaired or discarded. In the past there have been two approaches to rejecting a defective assemblage of signatures, one applicable to relatively thin assemblages usually of separate individual pages, and one applicable to relatively thick assemblages of signatures comprising a plurality of pages.
When the hoppers are feeding individual sheets and a misfeed is detected, feeding from hoppers downstream of the misfeeding hopper is inhibited. The defective assemblage is lifted onto a set of belts above the raceway by a set of fingers which pivot upward from the raceway. The defective assemblage is either discarded or the pages are manually sorted and returned to the hoppers from which they were fed.
This technique is satisfactory for relatively thin books or magazines, i.e., up to about two inches thick. However, it will not work for thick books or magazines up to three and a half or four inches thick, such as telephone books, because the thick assemblage will not move up the inclined fingers onto the upper conveyor without becoming disheveled. For thick books a second technique, called the repair technique, has been used for handling misfeeds from hoppers.
In the past when assembling a thick book, the hoppers each dispense a signature. In the event that a hopper misfeeds, the raceway conveyor is halted until an operator can manually repair the defective assemblage and restart the conveyor. Obviously, the repair technique can slow production.